What do the empty folders in the nuget package do?

[Marv51]

I was looking around the CommunityToolkit.WinUI.Controls.RichSuggestBox nuget package.

Just out of curiosity, how does this work? Why are there all these 18362 and even net7.0 folders, but they are all empty?

I thought, based on the targetframework nuget would choose the resources in the matching lib folder.